1. Field of the Invention
The present invention relates to an electro-luminescence display device and, more particularly, to an electro-luminescence display device and a method of fabricating the same capable of saving working hours needed to fabricate the electro-luminescence display device and preventing a waste of materials to improve a production yield of the electro-luminescence display device.
2. Description of the Related Art
In recently, there has been developed various flat panel displays with a reduced weight and bulk that are free from the disadvantage of a cathode ray tube CRT. Such flat panel displays include a liquid crystal display LCD, a field emission display FED, a plasma display panel PDP, and an electro luminescence (hereinafter, referred to as an EL) display devices. The structure and fabricating process of the PDP among these is relatively simple. Thus the PDP is most advantageous to be made light and large-sized, but has disadvantages that the light emission efficiency and brightness thereof are low and its power consumption is high. Whereas, the LCD has a disadvantage that the power consumption is high because the LCD is difficult to be made large-sized and adopts a backlight unit. Further, the LCD has a disadvantage that there is a high optical loss caused by optical devices such as a polarizing filter, a prism sheet and a diffusion panel, and its viewing angle is narrow. As compared with the LCD, the EL display device is generally classified into an inorganic EL display device and an organic EL display device. The EL display device has an advantage that its response speed is fast, its light-emission efficiency and brightness are high and it has wide viewing angle. The organic EL display device can display a picture in a high brightness of several ten thousands [cd/m2] with a voltage of about 10 [V].
A related art EL display device includes a display region having a pixel matrix and a non-display region except for the display region, on a substrate.
On the display region of the EL display device, an anode electrode and a cathode electrode are formed in a direction crossing each other. The anode electrode is separated from its adjacent anode electrodes by a predetermined distance on the substrate. An insulating film having an aperture at every EL cell region is formed on the substrate provided with the anode electrode. A barrier rib is located on the insulating film to separate each cell having the cathode electrode and an organic EL layer to be formed on the insulating film from adjacent cells. The barrier rib is formed in a direction across the anode electrode. The organic EL layer including an organic compound and the cathode electrode are sequentially deposited on an entire surface of the insulating film provided with the barrier rib. The organic EL layer includes a hole carrier layer, a light-emitting layer and an electron carrier layer which are stacked on the insulating film. According to the organic EL display device, when a driving signal is applied to the anode electrode and the cathode electrode, the electron and the hole are emitted from the anode electrode and the cathode electrode and the emitted electron and hole are re-combined each other in the organic EL layer, to thereby generate a visible light. The generated visible light is exited to an exterior via the anode electrode and is used to display a picture or image.
In the EL display device, as shown in FIGS. 1A to 1C, a pad part 2 of the non-display region is connected to a connection film such as a flexible print circuit FPC, a tape carrier package TCP and a chip on film COF in order to receive a driving signal from an exterior. Herein, the pad part 2 is connected to connection devices and includes a first pad 15 for receive the driving signal and a second pad 17 for aligning and testing an adhesive strength to the connection film as shown in FIGS. 1A to 1C. Herein, the second pad 17 can be formed in a variety of types, as shown in FIGS. 1A to 1C.
FIG. 2 is a sectional view illustrating an adhesion of the pad and the connection film of the driving circuit in a related art EL display device.
Each of the pads 15 and 17, as shown in FIG. 2, has a structure, in which a transparent conductive layer 21 connected to the anode electrode or the cathode electrode formed at the display region, and an opaque conductive layer 23 for raising a conductivity of the transparent conductive layer 21.
If a connection film 33 in which a base firm 35 and a copper material 37 are stacked is pressurized with respect to the pads 15 and 17 while positioning an anisotrophic conductive film ACF having conductive balls 25 between the connection film 33 and the pads 15 and 17, then the connection film 33 is electrically connected to the pads 15 and 17 by the conductive ball 25 pressurized between the pads 15 and 17, and the connection film 33.
Meanwhile, a separate destructive testing process is performed in the related art EL display device in order to confirm that the pads 15 and 17, and the connection film 33 are normally adhered through the use of the conductive film.
More specifically describing the destructive testing process, an adhesion of the pads 15 and 17, and the connection film 33 by the conductive film is performed using a parameter such as a predetermined pressure and strength. And then, the second pad 17 and the connection film 33 are separated from the conductive film. At this time, the parameter such as the adhesion level and the pressed strength between the second pad 17 and the connection film 33, and the conductive film is determined to settle a parameter for an optimum connection. The optimum parameter determined by the destructive testing process is used in the adhesion process to adhere the first pad 15 and the connection film 33 to the conductive film.
However, if the second pad 17 and the connection film 33, and the connection film are separated each other by the destructive testing process, then the second pad 17 and the connection film 33 thus separated cannot be used any more. Hereby, working hours needed to fabricate the EL display device becomes long by the number of times that the testing process is being performed. Further, the device subjected to the testing process should be abolished.